Basically, if you go visit Hindu temple, but you think of "one" God. If you have to go there with a friend, and respect "God/Goddesses" as well, because they all are created from Akal Purkh as well and mentioned in Gurbani as well. So if you sit in pooja, but remember "one" God during the prayer and pray to that one God in you heart throughout the pooja, is that okay or is that a sin or against Gurmat?